KNOWLEDGE 2.0: 109 ways to manage & make money on your information, research, advice, ideas, concepts, opinions, or to share your brain for free

Knowledge as in "knowledge sharing", "knowledge management", "knowledge worker" and "knowledge volunteer".

More aspects of the same in the PRODUCTIVITY 2.0 category.

20+ additions in this update, in italic.

5min - Upload, explore & share how to-videos ('videopedia')
7tipson - Browse & share tips
Able2know - Q&A
Allexperts - Q&A
Annotea - Create & share metadata
Annoyances - Q&A on Windows
Answerlytics - Q&A
Answers - Best answers to your questions
Answeru - Q&A on education
Askalibrarian - Q&A (Library of Congress)
Askeet - Ask & answer it
Askmehelpdesk - Provides answers & get tipped
Asktheworld - Q&A
Askville - Q&A by Amazon
Askvox - Write a question & hear the answer
Bitwine - Get or give video advice for a price
Blinkbits - Share knowledge
Brainkeeper - Capture, distribute & collaborate on corporate knowledge
Brainreactions - Participate in brainstorms & share ideas
Bubblus - Brainstorm together online
Circleup - Ask questions, get consolidated group's answer
Complore - Collaborate on research
Cooperationcommons - Knowledge base re cooperation & collective action
Cramster - Q&A
Dizzay - Q&A (instant answers through chat)
Duno - Q&A
Education - Q&A
Fluther - Q&A
Funadvice - Q&A
Gibeo - Share web annotations & content
Goodnotes - Bookmark, leave notes at & categorize web pages
Googlecoop - Share knowledge online
Grokker - Enterprise search & knowledge management
Growl - Semantic knowledge management
Grupthink - Explore & share topics & opinions
Guruza - Ask, or answer questions & get paid
Hanzoweb - Bookmark, tag & share knowledge online
Helenos - Semantic knowledge discovery
Helium - Buy, sell & trade knowledge
Hellup~ - Q&A
Hitchhikr* - Share knowledge & experiences on conferences
Hivelive - Post & share information
Hubpages - Share your genius
Ibridge - Aggregates early stage research & technologies
Illumio - Q&A
Instantnotes - Bookmark & leave notes at web pages
Instructables - Share what you make & how you made it
Intute - Validate & share academic information
Jabbits - Ask questions, watch answers
Jots - Information sharing
Kaboodle - Information sharing
Knowbrainers - Q&A
Knowbrainers - Q&A
Lookupahookup - Create or join an expert or experience group
Manyworlds - Explore business info reviewed & ranked by experts
Markthisdate~ - Publish & share events
Mousebrains - Thought starter for advertising creatives
Mozesmob - Mobile Q&A
Neighbor - Q&A (local)
Networkltd - Share research
Nownow - Ask a question, get three answers by email
Numinalmeme - Share & vote for ideas
Opinionaggregator - Q&A
Organizedwisdom - Publish & share your wisdom on health matters
Ownyourc* - Get help in making choices
Oyogi - Share Q&A
Postgenomic* - Share & rank life science knowledge
Qnalive - Microsoft's Q&A
Questionize - Q&A
Questionville - Q&A
Quomon - Q&A for IT issues
Rallypoint - Share knowledge
Reviewbasics* - Provide & get feedback on content & creative work
Riffs - Recommend, chat & share
Rootvaults* - Store, manage & share knowledge online
Sayoutloud - Post questions & issues, get answers or reactions
Shareyouropml - Share outlines, feed & taxonomy
Simplyexplained - Q&A
Skillsfeed - Share knowledge
Socialsaga* - Video Q&A
Sparkhive - Store & share thoughts, research, bookmarks
Spillr - Q&A
Squidoo - Share knowledge
Sutree - Knowledge sharing (thru video) community
Systemone - Enterprise knowledge sharing & management
Theanswerbank - Q&A
Thebeststuffintheworld - Submit, rank & share the best whatever
Theinjuries - Share knowledge & experiences about industrial injuries
Tipstrs - Publish & share tips on anything
Tracbac - Share, comment, revise & collaborate
Tutocle - Find, submit & share tutorials
Twocrowds - Share your predictions & have them assessed
Uclue - Q&A
Vatortv - Entrepreneurs share their ideas thru video
Videojug - Share know-how thru video
Visuarios - Publish & share how-to videos
Vitamint - Explore & share tips, and get paid
Wealthbasecamp - Share knowledge & ideas on wealth creation
Wechangetheworld - Submit, share & search ideas for a better world
Wehow - Profile & share your expertise
Whatshouldisay - Q&A
Wis - Q&A
Wisdomdb - Rate & share solutions to problems
Wondir - Share Q&A
Work - Publish & share articles on SME business
Yahooanswers - Share Q&A
Yedda - Q&A
Youtorials - Collaborate on tutorials
Zogix - Innovators' community

Italic = new. Update 061224, 070119, 070303, 070517, 060828.